QUATERNARY FAUNA OF GIBRALTAR. 61 
the open alveoli of the first and second premolars (pm. 1 and pm. 2), the latter much 
smaller than the former; the fourth premolar (pm. 4) recently broken off, but the 
fangs remaining in the alveolus; the first molar perfect and unworn, and about two 
thirds of the second molar. ‘The vertical diameter of the ramus at the second molar 
tooth is about 1-4, and the same at the diasteme. The diasteme measures 1’:0, and 
the symphysis 2-0. The teeth measure :— 



in, 
Tn. UM Re oe ne ee ee Oe Oe eM 599 ae 
a er as eee a Rey MD OLS: 
ST ee ee ee eee a5 
Sar Eon ee” Se Ree ee meres! EW ae 
Se ce ed a ee er ae ee Gl Dee ot | 
The teeth in other respects correspond exactly in pattern with those in the other 
mandible above described, the only difference at all worthy of note being that the first 
molar is slightly narrower. ? 
4, The next specimen is the anterior part, also of a right mandible (Pl. IV. figs. 3, 4), 
of a fully mature animal, containing the canine with the apex recently broken off, the 
open alveolus of the first premolar (pm. 1) close to the canine, the fourth premolar 
(pm. 4) fortunately quite entire though somewhat worn, with a portion of the 
alveolus of the first molar (m. 1) filled with stalagmite. There are no traces of the 
alveoli of the second and third premolars. ‘The fracture by which this portion was 
detached from the remainder of the jaw is ancient, the surface being covered with hard 
stalagmite ; and it may not very improbably have been the work of the Hyena. 
The diasteme measures 1-7; and the vertical height of the ramus at that part is 1’°7 ; 
the length of the symphysis 2’°5. The teeth measure :-— 
in. 
Canitiow a tn Hebel ete sy ee a OKT 
PIE Misinetdves hncecty lS @) tererer eal \ as? trl (ZO OGE20 
Pe aeaeT Way byeel he yeh be Se Cowl WR aie aIKIAD 
This specimen is particularly valuable in a diagnostic point of view, from its presenting 
the fourth premolar in a tolerably perfect condition. The dimensions of this tooth 
show its small size as compared with the other teeth; and in its pattern it also 
corresponds exactly with the usual form of the same tooth in U. arctos, as will after- 
wards be more particularly pointed out. 
5. The posterior half, or nearly so, of the left mandible of a young animal, but 
apparently not the same individual as that to which the immature mandible above 
described belonged, since the teeth appear to be rather larger. The specimen has been 
much comminuted; and different portions were found widely apart; so that at the 
time when the figures were prepared the several fragments had not been recognized 
as belonging to the same bone, and consequently one portion only of it is represented 
VoL. X.—Part 1. No. 2.— August 1st, 1877. K 
